What is cerebrospinal-vascular disease?
High morbidity & mortality
Typically manifests with abrupt focal neurological deficit
Common cerebrovascular disorders include:
• IschaemicStroke
• HaemorrhagicStroke
Common cerebrovascular anomalies include: • Intracranialaneurysms
• Arteriovenous Malformations (AVM)
What is a stroke?
• Second most common cause of death in the World
• Stroke kills more women than breast cancer and more men than prostate cancer
• Leading cause of adult disability
• In Australia 56,000 new and recurrent strokes this year– that is one stroke every nine minutes.
• 30% stroke survivors under 65
• 65% of stroke survivors suffer a disability which impedes
their ability to carry out daily living activities unassisted.
• The financial cost of stroke in Australia is estimated to be $5 billion each year
• More than 80% of strokes can be prevented
• Medical emergency
What percentage of CVA is haemorrhagic and non-haemorrhagic?
15% is haemorrhagic
85% is non-hemorrhagic
What is a TIA?
Transient Ischemic Attack
- “Angina” of the brain
- Focal neurological event lasting <24 hours
- Focal loss of central nervous function due to decreased blood flow to part of the brain
- Transient in nature
- High risk of CVA – precursor or warning event!
- Image…?? Brain – Carotids – Heart
CVA signs and symptoms
- Abrupt onset of hemiparesis, monoparesis, or (rarely) quadriparesis • Hemisensory deficits
- Monocular or binocular visual loss
- Visual field deficits
- Diplopia
- Dysarthria (unable to articulate speech)
- Facial droop
- Ataxia (lack of muscle control)
- Vertigo (rarely in isolation)
- Nystagmus (involuntary eye movement)
- Aphasia (unable to understand or produce speech) • Sudden decrease in level of consciousness
CVA diagnosis
- Medical history / Risk factors
- Physical examination
- Airway and breathing
- Reflexes, muscle strength, senses, and coordination
- Listen for sounds from any blockages of the arteries in the carotids • Blood pressure
- Listen to heart abnormal rhythm / sounds
- Blood tests
- ECG
- Imaging tests
CVA rise factors
Nonmodifiable • Age • Race / Ethnicity • Sex (female) • History of migraine headaches • Fibromuscular dysplasia • Heredity: Family history of stroke or transient ischemic attacks (TIAs)
Modifiable
• Hypertension (the most important)
• Diabetes mellitus
• Cardiac disease: Atrial fibrillation, valvular disease, heart failure, mitral stenosis, structural anomalies allowing right-to-left shunting (eg, patent foramen ovale), and atrial and ventricular enlargement
• Hypercholesterolemia
• Transient ischemic attacks (TIA) • Carotid stenosis
• Lifestyle issues: Excessive alcohol intake, tobacco use, illicit drug use, physical inactivity
• Obesity
• Oral contraceptive use/postmenopausal hormone use
Ischaemic stroke phases/stages
- Acute phase/stage (0 to 24/48 hours) (acute ischaemia, neutron death, cytotoxic and extracellular vascular oedema)
- Subacute phase/stage (24/48 + hours) (reparative process begins, resorption of necrotic tissue begins)
- Chronic phase/stage (4 to 6 + weeks) (resorption of necrotic tissues is complete, encephalomalacia or cystic cavity is formed)
Vascular territories (over 50% of strokes involve which region of the brain?)
The MCA (middle cerebral artery)
Cerebral perfusion
- The brain uses approximately 20% of the available oxygen for normal function
- Cerebral Perfusion includes:
- Cerebral Blood Volume (CBV) – volume blood in amount per 100g of brain tissue
- Cerebral Blood Flow (CBF) – blood supply brain tissue in a given time (usually ml per 100g per min)
- Auto-regulation of CBV & CBF is important
- In a healthy person CBF is remarkably constant
Types of ismchaemic stroke
- Large vessel
- Small vessel – Lacunar infarcts
- Thrombotic – from within the brain • Embolic – outside the brain
Small vessel - lacunar infarcts
• Occlusion of small sub-cortical non-branching arteries (<15-20mm)
• Occur most frequently in the basal ganglia and in the internal capsule,
thalamus, corona radiata, and pons
• Accounts for around 20% of ischaemic strokes
• Symptomatic or non-symptomatic
• Higher risk of more serious large vessel stroke
Large vessel
Occlusion of large artery in the brain
• Thrombotic origin most common
• MCA most commonly occluded major artery • Clinical emergency
Haemorrage stroke
- Approximately 15% of all strokes
* Poor prognosis compared to ischaemic stroke • Requires rapid intervention
Imaging for a stroke
- Plays major role in patient treatment and diagnosis of brain injury.
- CT
- MRI
- Ultrasound
- Catheter Angiography (DSA)
- PET / SPECT
- X-ray
Diagnostic imaging for a stroke
Purpose:
DIAGNOSTIC IMAGING
1. Confirm clinical diagnosis
2. Distinguish between haemorrhagic & thromboembolic ischaemia
3. Identify underlying cause of disease e.g. stenosis/occlusion in CVA
4. Direct management/intervention e.g. thrombolytic therapy in CVA
Ideal diagnostic test for a stroke
• 24/7 Availability?
• Safe for acutely ill patients?
• Quick?… ‘Time is Brain’
• Sensitive to cerebral haemorrhage and be able to exclude other differentials?
• Demonstrate anatomical and pathophysiologic aspects of hyper-acute stroke?
• Demonstrate salvageable brain tissue?
• Demonstrate vasculature?
– Vessel occlusion and location
– Origin of emboli or thrombus location/type
CT for a stroke
Non-contrast • Fast +++ • Available 24/7 • Safe • Sensitive for haemorrhage Contrast • Demonstrate vessels • Demonstrate perfusion
